Knob 2 of 5
Which brain is doing the work.
· Novel or ambiguous
· Subtle judgment
· High-stakes output
· Well-defined work
· Fast iteration
· Most of your day
Rule of thumb
Default to the Workhorse. You'll be surprised how often it's enough. Reach for the PhD when you hit a wall — not as a starting point. Every prompt is an opportunity to ask: does this actually need the smartest model in the building?